Study selection
Electronic searches resulted in 5357 citations. We found no additional studies through contacts with experts and third sector organisations. Fifty papers were included for full text assessment. After full text screening, 14 studies [26-39] out of these 50 were included in narrative synthesis. See Figure 1 for details of the process.
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Figure 1: PRISMA Flow diagram of review process
Description of included studies
Ten studies were from USA, followed by two from Australia and the UK respectively, and one from Poland. We found no randomised trials. Studies were either surveys or uncontrolled before and after designs. Sample sizes across studies varied widely, ranging from 23 pupils to 33 572 pupils (median = 1811 pupils).
Studies typically included more females than males. Most studies (n=9) [26, 27, 29, 30, 32, 34-37] included high school pupils. White pupils were included less often (mean 36%, median 30% across studies) than non-white pupils. Five studies [28, 32, 36, 38, 39] focused on deprived populations, reported as majority (>50%) children being on free school meals and/or low earning.
Temporary suspension from school was most frequently studied (n=11) [26, 28, 30-32, 34, 36-40], followed by verbal reprimanding or punishment (n=2) [33, 35] and various mixed (multiple combined) strategies (n=2) [27, 29]. We present result for these categories separately below.
The most common studied outcome was depression (n=7) [27-29, 31, 32, 34, 37] using various scales: PHQ-9 (Patient health Questionnaire); CESD (Center for Epidemiological Studies Depression); SDQ (Strengths and Difficulties Questionnaire); California Healthy Kids Survey (WestEd) (Depression subscale); and Add Health survey. Two studies assessed internalising symptoms ( i.e., problems of withdrawal, somatic complaints, and anxiety/depression)[41], one using Teacher observation of classroom adaptation checklist (TOCAC) [28] and Youth Self Report (YSR) in the other [38]. One study assessed externalising symptoms (i.e., problems of aggression, impulsivity, and inattention)[41] on adapted Behavior Assessment System for Children: second edition (BASC 2) scale [26]. Anxiety was assessed in one study [33] using a Polish version of State-Trait Anxiety Inventory for Children. General mental wellbeing was assessed in three studies [30, 35, 36], one using the Warwick and Edinburgh Mental Wellbeing Scale [30], and two using author developed scales [35, 36]. Five studies [27, 32, 33, 36, 39] assessed impact of disciplinary strategies on educational attainment. See table 1 for details of included studies.
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Risk of bias in included studies
Studies were mostly at high risk of bias across all domains (see Figure 2). Only one study [28] was considered at an overall moderate risk of bias. None were considered at a low risk of bias. For most studies there is risk of bias due to confounding. For cross-sectional studies and surveys the risk of reverse causality is a key problem, i.e., we can’t be sure whether poor mental health was the cause of 'bad behaviour' and thus the reprimand or suspension, rather than the consequence.
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Figure 2: Risk of bias in included studies
Effect of disciplinary strategies on pupil mental health and wellbeing outcomes
i. School Suspension Strategies
Five studies [28, 31, 32, 34, 37] reported on depression due to suspension.
Odds of greater total difficulties (SDQ) were found to be significantly higher for those who were suspended in two studies [31, 34]. Rushton et al. [37] also found that being suspended from school was associated with increased odds of depressive symptomology. Two studies [28, 32] found self-reported depressive symptoms were not related to suspension.
ii. Verbal reprimand strategies
None of the two studies assessing verbal punishment strategies reported on depression.
iii. Mixed strategies
Two studies [27, 29] reported depression assessing two slightly different strategies that included suspensions and some other forms of punishments together. Both found that punishment-based policies led to more depressive symptoms, but at different time points.
Chen et al. [27] found that Black pupils attending a school that disproportionately punished Black students had greater depressive symptoms as an adult ten years later (β= 0.11,95% CI: 0.04, 0.18), compared to their White peers. Eyllon et al. [29] found strict (vs lenient) policies to increase depression in pupils so that each unit increase in school’s policy being strict led to a 1.03 unit rise in pupil depression scores on average (95% CI: 0.15, 1.91).
Impact on population subgroups
The two studies reporting data on ethnicity were not in agreement. While Chen et al. [27] found Black pupils to be disproportionately affected by disciplinary punishments and the consequent depression in later age, Eyllon et al. [29] found no link between ethnicity and higher depression due to strict school policies within one year.
No suspension or mixed strategy studies reported this outcome.
A single study set in Poland [33] found that higher school stress brought on by verbal reprimand strategies led to higher anxiety in pupils (R = 0.30, p <.001).
A single study [31] found children who had been suspended from school had higher odds of diagnosis of a new psychiatric disorder (OR 7.09; 95%CI 5.07 to 9.91; p < 0.001) compared to those not suspended.
No studies of verbal reprimand or mixed strategies reported this outcome.
One study [30] assessing the effect of suspension found a non-significant (p=0.15) lower wellbeing (on Warwick Edinburgh Mental Wellbeing Scale) and significantly (p=0.003) greater use of mental health services for suspended children compared to pupils who have never been suspended. Another found children who were suspended were twice as likely to have poor mental health [36].
A single study [35] assessing link between verbal disciplinary strategies and pupil mental wellbeing (on author developed scale) reported no outcome data.
No study on mixed strategies reported this outcome.
One study on suspension [38] found that each additional suspension per school led to increase in internalising scores by 0.05%, while another [28] found that suspensions were not associated with internalising problems.
No verbal reprimand or mixed strategy studies reported this outcome.
A single study found that in schools which suspended proportionally more Black pupils than White pupils, Black pupils overall showed higher externalising symptoms [26].
No verbal reprimand or mixed strategy studies reported this outcome.
Effect of disciplinary strategies on pupil social and behavioural outcomes
i. School Suspension Strategies
Three studies [28, 34, 39] found suspension was associated with poorer (more disruptive, less pro-social) behaviour.
Two studies found suspensions were associated with lower perception of social belonging at school [26, 34].
School-level Black–White suspension gaps (i.e., excess risk of out-of-school suspension among Black students relative to White students,) were associated with Black students’ perceptions of less school equity in a single study [26].
A single study [32] found suspensions led to greater marijuana use but had no association with tobacco or alcohol use. A single study [38] found no association between out-of-school suspension and self-esteem.
ii. Verbal reprimand strategies
A single study (Roache) found that aggressive verbal punishments from teachers led to increased disruptive behaviour in the classroom (r=0.48, p<0.05), being more distracted from class work (r=0.72, p<0.05), and reduced pupil interest in the subject being taught (r=-0.58, p<0.05).
No studies in this category reported social outcomes.
iii. Mixed strategies
No studies of mixed strategies reported social outcomes.
Effect of disciplinary strategies on academic outcomes
i. School Suspension Strategies
Of the three studies assessing educational outcomes, one comprehensively reported data and [32] found no link between suspension and grade scores. This effect remained non-significant (although direction was opposite) after adjusting for demographic factors including ethnicity. One study [36] did not report data on the effect of suspension on grades, and the other [39] said they found lower scores on a composite of academic performance habits and skills but did not report data to support this finding.
ii. Verbal reprimand strategies
Piekarska et al. [33] found that verbal punishments from teachers caused school stress which negatively impacted academic performance as grade point average.
iii. Mixed strategies
While Chen et al. (2021) reported no direct effect of greater punishment on long-term educational attainment, they did find that for children who were not academically oriented, greater punishment was associated with lower educational attainment. This study included only Black American pupils.